Separatist militants blew up a historic building linked to Pakistan’s founding father in the country’s violence-plagued southwest after shooting dead a guard in a predawn attack on Saturday, officials said.

The attackers, armed with automatic weapons entered the 19th century wooden Ziarat Residency after midnight and planted several bombs, senior administration official Nadeem Tahir told AFP.

Mohammad Ali Jinnah, the driving force behind the creation of the Pakistan, spent his last days in the building which was declared a national monument following his death, one year after the country’s independence in 1947.

The building is in Ziarat town, 80 kilometres southeast of Quetta, the capital of insurgency-hit Balochistan province. “They shot dead the guard who resisted the intruders,” Tahir said. Police official Asghar Ali said militants planted several bombs and detonated them by remote control. “The Ziarat Residency, which had its balcony, floor and front made of wood, has been totally gutted,” he said.

At least four blasts were heard in the town, he said. The building caught fire and it took five hours to bring the blaze under control as Ziarat, a small hill station, has no fire brigade. A separatist-group later claimed responsibility for the attack.

“We blew up the Ziarat Residency,” Meerak Baluch, a spokesman for the Balochistan Liberation Army said from undisclosed location. “We dont recognise any Pakistani monument.” No one has been arrested, officials said.

Balochistan, Pakistan’s largest but most undeveloped province on the Iranian and Afghan border, is racked by Islamist and sectarian violence as well as a long-running separatist insurgency, and attacks on official buildings and security forces are common. The attack came after the Pakistan Muslim League-N (PML-N) party of prime minister Nawaz Sharif won the May 11 elections in the country.

Sharif appointed Baloch nationalist leaders as governor and chief minister, raising hopes that a coalition between PML-N and nationalist parties could address some of the long-held grievances in the province about its treatment by the federal government.

Prime Minister Sharif and several political leaders strongly condemned the attack while Interior Minister Chaudhry Nisar promised arrest of the attackers. Hundreds of people including, some party leaders and students staged a protest rally in the town demanding “exemplary punishment of culprits involved in the attack,” witnesses said.

Provincial Chief Secretary Babar Yaqoob told reporters that “people involved in the colossal destruction of our national monument will not be spared”. “The government has ordered immediate steps to rebuild the Ziarat Residency in its original form,” he said.

“It was an undisputed structure, it had never received any threat in the past. Local people had special love for this site because it had been attracting local and foreign tourists,” he said. Ziarat, located at more than 2,500 metres above sea level and surrounded by Juniper trees is a popular tourist site.

The two-storey structure was built in 1892 and was formerly used by officials from the British Colonial rule in India. The furniture used by Jinnah and kept at its original place as national heritage since his death in September 1948, has also been destroyed, officials said.